Lines etched in bedrock as individual particles embedded in the ice at the base of a glacier scratch the underlying bedrock. These lines are
parallel to glacial flow and thus indicate the orientation (but not necessarily the direction) of flow. Determining the orientation of
ice flow may be important if you're trying to reconstruct the glacial history of a place where no one was around to observe the glaciers
when the striations were formed.

The striations in the photo are on rocks in the Indian Peaks Wilderness, Utah. Although the striations allow you to determine
the orientation of flow, you need other clues to determine the actual direction of flow. In mountainous regions, flow will always be from
higher to lower elevations. Although the surrounding topography is not visible in the photo, that topography indicates the ice flowed
from the bottom right to the upper left of the photo.